The present invention relates to automatic photoflash calculator systems and more particularly to a calculator apparatus which changes the sensitivity of the photoflash light sensor in accordance with the photographer's use of the calculator.
Automatic photoflash systems are generally well known in the art. Basically, a light producing means is selectively actuated to furnish light for the illumination of a scene to be photographed. A light sensing means senses light received back from the scene and, upon receipt of a predetermined quantity of light, generates a quench signal which is effective to terminate the light being produced.
In order to provide the photographer with greater flexibility in selection of f-stop/distance settings with any given ASA speed of film being used in an associated camera, the art has suggested controlling the amount of light output produced by the flash by using a light attenuator in front of the device's light sensing means. See for example, U.S. Pat. No. 3,769,888 issued to one of the present inventors on November 6, 1973, and assigned to the same assignee as the present invention.
Although such calculators operate accurately, they are found to be generally complex in their structure and operation, making both their manufacture and ultimate use moderately sophisticated. The provision of a more simplified structure permitting easy operation would be highly welcomed.